"The SPAD array is not an imaging sensor [...] the whole sensor acts like one component" --> this is then a digital SiPM and force the transmitter to be a 2D scanner (single laser spot scanned in both directions) which requires extremely high speed. The exposure time for pixel is therefore very small if you want to meet the requirements on the global frame rate. Relying on temporal concurrency or time-correlation is highly limited by the 2D scanning unless high power are employed. What's most interesting here is the OPA laser scanner together with a SPAD array in terms of speed/optical-power trade-off. Unfortunately this has not been cover in depth. The results seem very promising, nevertheless. Very nice approach.